146 Mr. R. C. L. Perkins on 



The followiiifi- characters appear to be coininou to all 

 the Hawaiian Crabroiiini : 



^ $. Ocelli in ii tiiiingle, which is much widest at the base, the 

 posterior ocelli being nearly twice as far apart as either one is from 

 the anterior ocellus ; recurrent nervure received very near the apex 

 of the cubital cell ; superorbital fovea) at most represented by elongate 

 smoother spaces, or shallow and often shining impressions. 



^ . Antennye 12-jointed, 3rd joint always long, much hmger than 

 the 4th, but shorter than the 4th and 5tli together, not less than 

 twice as long as the 2nd ; 6th always emarginate beneath and pro- 

 duced more or less below the base of the 7th, often forming a very 

 prominent tooth ; spur of middle tibiie well-develojied ; apex of 

 mandibles always bidentate. 



9 . Pygidial area always defined by distinct carinse, but varying 

 in form from more or less wide and triangular, to very narrow and 

 elongate. 



1. (2) Antennal fossae in front view of the head well separated from 



the eye-margins by a space at least nearly as wide as one of 



the antennal forsa3. 



Clypeus with suberect hairs, the surface not concealed by 

 dense ajjpressed jjilosity of metallic colour, the apex 

 widely rounded ; propodeum with a median sulcus. 

 ^ with the 6th joint of the antennae very little pro- 

 duced beneath at the apex, not forming a strongly 

 prominent tooth. 5 with the 5th segment (except in 

 one species) densely clothed with red hairs ; mandibles 

 3-dentate at apex, the upjer tooth generally not 

 strongly developed, no ]>ost-median tooth on the upper 

 edge ; pygidial area very narrow and elongate. 



Nesvcrabro P. 



2. (I) Antennal fosspc in front view contiguous to the eye-margins ; 



clypeus always hidden under a dense covering of silver or 

 golden appressecl pilosity. 



3. (4) (t . Sixth joint of the antenna) produced into a long tooth, aji- 



pearing simple in one aspect, but it is really flattened and 

 of subquadrate form ; front legs much modified. 



Oreorrahro, gen. nov. (Type Ch-ahro abnormia, Blackb.) 



4. (3) ($ . With the 6th joint of the antenna^ feebly or distinctly 



toothed, but the tooth not flattened and compressed. 



5. (6) (^ . Second segment of abdomen beneath flattened and inclined 



at an obtuse angle ti> the flattened or impressed tlurd seg- 

 ment; 6th joint nf antenna' very littlt; produced at apex, 

 not projecting much below the base of the following : 



